On Sun, Sep 26, 2010 at 12:20 PM, Michael Snoyman <michael at snoyman.com> wrote:
> On Sun, Sep 26, 2010 at 10:10 AM, Rehno Lindeque <errantkid at gmail.com> wrote:
>>> One more question. Is it possible to manipulate the request header
>> when doing a redirect? For example, at one I have (redirect
>> RedirectTemporary $ AuthR LoginR), but "X-Requested-With" isn't being
>> passed through...
>>>> No, the request headers are set by the browser, and you can't directly
> affect them. What you *could* do is set a session variable or
> something. However, your best bet is probably to redirect to a URL
> with a query-string parameter indicated the request-with information
> and then check both the request header and the query string parameter.
>> Michael
>
Thought I'd mention that this worked out very nicely in Yesod. I
modified the default layout to return only the page contents of a
request if it is an ajax request, but add all the surrounding html if
it isn't. I also used a session variable for the redirected ajax
requests. At first I just wanted to call the correct handler directly
instead of redirecting if it was a ajax request but since getLoginR is
private to Yesod.Helpers.Auth I had to redirect and the session
variable was actually very simple to set and check.
I.e. If anyone is curious it looks like this:
> isAjaxRequest :: GHandler master sub Bool
> isAjaxRequest = do
> request <- waiRequest
> sessionVar <- lookupSession Session.ajaxRequestKey
> return $
> (isJust $
> listToMaybe $
> filter (\(k,v) -> k == mkCIByteString "X-Requested-With" && B8.map toLower v == "xmlhttprequest") $
> requestHeaders request)
> || isJust sessionVar
>> instance Yesod where
> defaultLayout widget = do
> mmsg <- getMessage
> mAuth <- maybeAuth
>> -- Get the page contents
> pc <- widgetToPageContent $ do
> widget
> addStyle $(Settings.cassiusFile "default-layout")
>> -- Check whether this is a ajax request
> isAjax <- isAjaxRequest
> deleteSession Session.ajaxRequestKey
>> -- Return either the page body if it's an ajax request or embed in the default layout if it's a normal request
> hamletToRepHtml $
> if isAjax then pageBody pc
> else $(Settings.hamletFile "default-layout")
Of course when you redirect you have to set the session variable like this:
> isAjax <- isAjaxRequest
> if isAjax then setSession Session.ajaxRequestKey "true" else return ()
> redirect RedirectTemporary $ AuthR LoginR
Rehno